textproduct: Albany

WHAT HAS CHANGED

Wind Advisory has been issued for the southern Adirondacks, Mohawk Valley, Helderbergs, Lake George Saratoga Region, northern Taconics, and the Greater Capital Region in eastern NY and the southern Greens of Bennington and western Windham Counties for south to southwest wind gusts 40-50 mph tomorrow late morning through the afternoon. Gusts below 46-57 mph Wind Advisory criteria may bring down fully leafed tree limbs/trees with the deepening and intensifying cyclone passing to the north of the region. Gusts to 30 to 40 mph possible outside the Advisory area with some expansion needed later potentially to Schoharie and Berkshires Counties. We went above the NBM 90th percentile winds/wind gusts to achieve gusts 35-50 mph.

Slight Risk continues across the region for low topped convection with damaging winds the main threat, though a 2% to <5% probability contour for tornadoes has been added to south/southeast VT.

The timing for any potential severe convection looks to be 11 am to 6 pm Thu across eastern NY and western New England.

KEY MESSAGES

1) A few showers and thunderstorms this afternoon into the early evening, but strong storms are not expected.

2) A strong area of low pressure passing by to the north will bring windy conditions for tomorrow, which could result in some downed trees, large tree limbs and power lines. A Wind Advisory has been issued from the Mohawk Valley, Capital Region, and southern Greens northward 8 am to 8 pm EDT Thu.

3) There is Slight Risk for severe thunderstorms for much of the region, with damaging winds being the main threat, though an isolated tornado can not be ruled out.

4) Brisk and cool conditions Fri into the weekend with a few showers north and west of the Capital Region before rains returns to close the weekend and open next week.

DISCUSSION

KEY MESSAGE 1...

A weak mid and upper level disturbance will continue to bring some widely scattered to scattered showers and some thunderstorms this afternoon into early tonight. Latest SPC RAP mesoanalysis indicates limited instability with generally less than 500 J/kg, as sfc dewpoints are in the mid/upper 40s to lower/mid 50s across eastern NY and western New England. The limited instability will continue to reduce any severe threat. A few winds gusts 30-40 mph may occur with an isolated storm (well below severe limits). High temps top out in the 70s to lower 80s in the mid Hudson Valley with a few cooler readings over the northern mtns. Mid and high clouds will quickly increase tonight ahead of a warm front, as the mid and upper level flow shifts from zonal to southwesterly ahead of the strong upper level trough.

KEY MESSAGE 2...

A powerful and anomalous low pressure system will approach from the Great Lakes Region tonight and shift north and east across Georgian Bay and southeast Ontario by 12Z/8am Thu, as the mid and upper level trough will become negatively tilted. The sfc cyclone will deepen and intensify to 980-985 hPa by the late morning into the afternoon over southern Quebec. The MSLP falls are 2 to 4 STDEVS below normal based on the latest NAEFS and the 850 hPa low-level jet rapidly increases across the region from the south, and then shifts south/southwest at 45-60 KT in the late morning into the afternoon. The V-wind anomalies /southerlies/ are +3 to +5 STDEVs above normal on the latest NAEFS through much of eastern NY and western New England Thu morning/early pm. Downsloping off the northern Catskills, and funneling of the southerly winds up the Hudson River Valley into the Capital Region in the narrow north-south valleys in the Mohawk Valley may produce some wind advisory gusts or near wind advisory gusts causing downed tree limbs, trees and power lines. The gusts may be closer to 40 mph (below Wind Advisory gust thresholds) but with fully leafed trees and a deep and anomalous low these synoptic level winds could cause issues. A surge of warm advection pcpn is expected tonight prior to daybreak, which should limited the wind gusts initially, and this is why we started the advisory at 12Z/8 AM after extensive collaboration with WFOs BUF/BTV/BGM/GYX. We may need to add in a few zones later (i.e. Berkshires and Schoharie Counties.

The 925 hPa winds are also in the 35-50 KT range by the late morning based on some of the short-range guidance. The latest NBM indicates probabilities of 30-80% for >40 mph gusts through the afternoon are highest across the Capital Region, northern Taconics, Lake George Saratoga Region portions of southern VT and southern Herkimer County, as well grazing the northern Berkshires. The greatest impacts will continue to some downed trees, large limbs causing some power outages to be possible due to the fully leaved trees. The advisory runs until 8 pm Thu.

KEY MESSAGE 3... SPC continues a Slight Risk (Level 2 of 5) across the entire forecast area tomorrow. A high shear and low CAPE environment will be in place, as the forecast area gets briefly in a warm sector. The latest HREFs show a strong mid and upper level jet streak over the forecast area during the afternoon. The northern third of the forecast area will be located closest to the cyclonic exit region or left front quadrant of a 500 hPa jet streak of 70-90+ KT. Impressive dynamics will be aloft with 0-6 km bulk shear values of 40-60 KT, but the HREFs only indicate mean SBCAPEs of 250-500 J/kg or less. Some of the CAMs continues to show slightly better instability of 500-1000 J/kg of SBCAPE and even MLCAPE. Sfc dewpoints will rise into the upper 50s and 60s in the narrow warm sector. The question will be if the updrafts can be tall enough to bring down the strong winds aloft. A strongly forced line or a few linear segments seems possible between 11 am to 6 pm EDT Thu, if enough heating occurs and instability is realized. The 0-1 km/0-3 km helicity values are also impressive on the HREFs and CAMs, as the Sig Tor Parameter /STP/ on the HREF is 1-2 with pockets to 3 or slightly greater. Tornado probabilities have been added to portions of VT into NH. Even outside this contour, a isolated tornado or two may be possible the strong shear/helicity and the low LCL's in the morning/early pm.

In terms of the impacts, damaging winds bringing down trees, tree limbs, power lines and power poles would be the main impacts. Subsequent power outages may occur from the wind gusts >58 mph. The severe threat should diminish from west to east quickly in the mid to late pm with strong cold advection in the wake of the cold front and deepening low to north. Brisk west to southwest winds will continue at 10-20 mph with some gusts 25 to 40 mph. Highs will be in the mid 70s to lower 80s in the valleys with the warmest readings near I-84. Expect highs in the mid 60s to mid 70s over the higher terrain. Lows fall back into the 50s to lower 60s with a few cooler readings over the Adirondack Park.

KEY MESSAGE 4... The low pressure system occludes and becomes vertically stacked over east/southeast Quebec and the Gulf of St Lawrence by Friday late morning into the afternoon. In the cyclonic flow, it favors some instability rain showers and lake effect enhanced showers may pop-up north and west of the Capital Region. An isolated thunderstorm is also possible. It will continue to be brisk with west winds 10-15/15-25 mph with some gusts 25-40 mph. The channeled westerly flow down the Mohawk Valley/Capital Region into the northern Taconics/Berkshires will favored the strongest winds/gusts. The winds may hit below wind advisory thresholds on Fri...but it will be windy for mid-June standards! Highs will be near to slightly below normal for June with 60s and 70s for highs and a few 80 readings in the mid-Hudson Valley. Saturday, features mixed clouds and sunshine with a few showers/thunderstorms and over the northern mtns and zones. Temps will be cool and run slightly below normal to open the weekend. Rain chances increase late Sun/Sun night into Mon with a low pressure system approaching from the south and west. A soaking rainfall may occur for portions of the forecast area, maybe ponding some water in a few spots.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Through 18z/Thursday...Flying conditions should be mainly VFR for the rest of the afternoon with the exception of some isolated showers seen upstream on KENX radar passing through late this afternoon and evening. If any of these showers pass over the terminals, visibilities could be lowered briefly to MVFR. This is mentioned in a PROB30 for KGFL, KALB, and KPOU. A brief rumble of thunder can't be ruled out, but coverage looks too low to include explicitly in the TAFs. Broken and overcast low level stratiform clouds just ahead and along the approaching cold front begin to overspread the region after sunset tonight with increasing chances of showers. With plenty of moisture around, fog/mist could develop into the early morning hours at KGFL and KPSF, but depending on how soon winds pick up and how much cloud cover lingers, fog/mist could be limited. The next batch of showers will be more widespread arriving from between about 06z-10z across the terminals from the northwest. Model soundings suggest flying conditions will likely be lowered to MVFR and hi-res model guidance shows showers becoming more moderate at times especially where thunderstorms develop. Scattered thunderstorms pass through all the terminals starting by about 13/14z. With moderate rain and gusty winds, lowered flying conditions to MVFR/IFR are expected through the end of the TAF period.

Current southerly/southwesterly winds with speeds 7-11 kt and gusts up to 20 kt remain through sunset tonight before winds slightly decrease to 5-8 kt for the first half of the night. Winds then quickly pick back up by morning and are sustained 15-20 kt and gusting near 35-45 kt by afternoon, especially highest where thunderstorms occur. Wind shear at 2000 ft AGL is likely after about 10z tomorrow morning across all the terminals.

Outlook...

Thursday Night: Low Operational Impact. Breezy. NO SIG WX. Friday: Moderate Operational Impact. Windy With Gusts To 32 kts. NO SIG WX. Friday Night: Low Operational Impact. Breezy. NO SIG WX. Saturday: Moderate Operational Impact. Windy With Gusts To 31 kts. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. NO SIG WX. Sunday Night: Moderate Operational Impact. Chance of SHRA. Monday: High Operational Impact. Likely SHRA...TSRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Wind Advisory from 8 AM to 8 PM EDT Thursday for NYZ032-033- 038>043-048>054-082>084. MA...None. VT...Wind Advisory from 8 AM to 8 PM EDT Thursday for VTZ013-014.